78. How many engines have you; one or two?-One for use; but they are put T. Hawksley, Esq. in duplicate, so that if one became disarranged, or required repair, the other might go on with the operation; they are two very little things of five-horse active power.

79. How many pumps are there?-They have one pump each for the filter beds; and one pump each for the fountains.

So. You are of opinion that 300 l. a year will cover the whole of the yearly expense of pumping and filtering ?-Yes; I would engage to do it for that, although it is not my business.

S1. With regard to the chances of getting out of order, bave you considered that question; what are the chances of the pumps or engines getting out of order-None at all, because, as I have mentioned, we have a duplicate engine. 82. And duplicate pumps -Yes, duplicates of everything.

83. You do not consider that an occurrence likely to happen?-Not at all.

84. The filters will work continually from year to year? Yes. I supplied the town of Nottingham for 20 years with one engine, the whole of the population supplied by the company being dependent upon it, without any mishap whatever; the water was never a day off.

85. I understand you clearly to say, that it is your opinion that eight feet of mud in the bottom of that lake does not, in any perceptible degree, injure the water-In any sensible degree; I do not mean to say that by the most refined analysis, you could not discover an infinitesimal action; but I do not think it is a thing that any man could regard in a practical point of view.

86. You attribute the whole of the present foul state of the water to these vegetable growths of which you have spoken?--Yes, except at the upper end, where I have already mentioned that under exceptional circumstances there are overflows of the sewer, and then some very nasty matter occasionally finds its way in.

87. Besides the overflow of the Ranelagh Sewer ?—No; I mean from that of

course.

88. And which will be prevented?—Yes.

89. You stated, I think, that the Upper Serpentine above the bridge had a fouler bottom than the lower-Yes; it is a very nasty place.

90. And it is shallower?-So shallow that where the works have been made there was not, at the upper end, six inches of water upon the mud.

91. You also stated, I think, that deep lakes are much purer than shallow ones?-Certainly.

92. Therefore the water in the upper part certainly would deteriorate faster than that in the lower?-Yes, it does in hot weather; you may see that the water is much fuller of this vegetable matter in the upper portion than in the lower.

93. Have you seen the lake in St. James's Park?—Yes.

94. That is shallow. I believe?-Yes.

95. Do you consider that that water is likely to deteriorate faster than if it was deep--Certainly; and so it did.

96. And does-Yes; last summer the water was in a frightful condition in St. James's Park, particularly at the latter end of July, and during the whole of August; and in September I took several persons to look at it, and amongst others a gentleman from the Office of Works.

97. It is your opinion, that so far as the purity of the water in the Serpentine goes, it is not of any consequence that that mud should be removed which is now at the bottom, nor that the lake should be made shallower?-For the purposes for which I suppose the having pure water is desirable, if you could make it ten times as deep it would be better.

98. But the mud?-That would be perfectly immaterial; it would be just the same as the lias formation; that was all mud, not exactly of the same kind, but of an analagous character; it contains certain quantities of sulphur and certain quantities of phosphoric acid.

99. Captain Archdall.] Was your attention called to the offensive smell said to arise from the Serpentine when you had a communication with the Chief Commissioner of Works?—Yes.

103. Did you acknowledge that that smell did exist ?-Only to a very slight extent, except at the upper part.

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T. Hawksley, Esq.

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101. From what did it arise?-From the circumstances that I have mentioned; during a storm of last summer, and there were several very violent thunder storms, and one so violent on a Sunday that I think it will be within the recollection of every one, there was a large quantity of focal matter poured in at the upper end, and it certainly did smell in a very disgusting manner. Then besides that, there is occasionally a mawkish smell, particularly on damp summer evenings, which arises from the growth of the conferva, a sort of smell the same as that on the sea shore when the tide recedes; that smell arises from this vegetation which I have mentioned, and any person experienced in these matters would recognise it at once you perceive it on the banks of a river.

102. You stated that the Serpentine was large enough to keep itself pure?— Yes.

103. You propose to introduce two millions of gallons of pure water into that lake per day?—I do not say that, because I wish to distinguish between the matter held in solution, which will remain, and the matters held in suspension which require to be taken out, and which it is the object of these works to remove, and then leave nature to deal, as she is dealing, with the matters held in solution; nature deoxydises those matters which are held in solution with great rapidity, as I can state from the result of a large experience.

104. You have stated that these aquatic productions grow with amazing rapidity?—Yes; I will mention an instance: at the Nottingham Waterworks we have an inlet which brings in about half a million of gallons a day of perfectly pure water from gravel; it has never seen the light; that water runs in through a sort of small bay, not larger than this table; with such rapidity, however, are these plants generated, the moment this water comes to the light, that on one occasion I measured the growth of a conferva, and I found that it had grown 18 feet in 48 hours.

105. Do you conceive that you will destroy this vegetable production in a greater proportion than its growth by the removal of the two thousand millions of gallons out of the sixty thousand?-All that matter which is detached and floating in the water, and giving its green tint, will be removed; the stones near the beach, are covered with green slimy matter, and that will be untouched by any process which can be adopted, short of applying some alkaline matters to it; quick lime will destroy it immediately; but nothing that you can put in, no kind of water, will have the slightest effect upon it; that matter is attached to the stones and growing from them.

106. I mean that which you propose to remove?—That which is the cause of the impurity of the water I propose to remove at the rate of one-thirtieth of the whole every day.

107. At the end of a fortnight will it not be reproduced in nearly the same proportion?-No; because now there is a vast accumulation, which has never been removed at all except by the overflow.

108. I presume that there are natural causes which tend to destroy these vegetable substances; otherwise, as you have already said, the Serpentine is in a better condition now than it has been for a few years past?—Yes.

109. You have stated that the state of the water is very slightly, if at all, affected by the mud which lies at the bottom of the Serpentine ?—Yes; that is a

fact.

110. Supposing that some 100 or 200 bathers were to stir up a quantity of mud near the shore, would it subside without doing any harm to the water?—Yes; it subsides directly.

111. Without affecting the purity of the water?-Yes; I have stirred it up myself; I did it in the course of this examination.

112. Was the possibility of obtaining this supply of two millions of gallons of water from any other source than pumping it out of the Serpentine considered?Yes; it was considered and reported upon, and I was very desirous, because I know what the public feeling is on these questions, to introduce, if I could bave found feasible means of doing so, other water in the place of purifying this; not that I do not know that the purification in this manner would be effectual, but because I know that the other would be more agreeable to the public feeling, as the public are not informed upon this subject; it is one with which the public are not popularly acquainted.

113- Do

113. Do you consider that this plan, as now being carried out, will be entirely T. Hawksley, Esq. effectual in remedying the evils complained of, or only in a degree?-It will be effectual to the extent and in the manner mentioned; that is to say, it will be as effectual as any other and more effectual than some.

114. I think you stated that when you were first introduced to the Chief Commissioner, your attention was directed solely to the purification?—Yes, of the

water.

115. And you stated that the Commissioner expressly said that he was not prepared to face the large expenditure that would be necessary for levelling and filling up the body of the Serpentine to a certain depth ?—Yes; he stated that spontaneously as a reason for my instructions.

116. Can you state, for the information of the Committee, the amount of any estimates which have been made for that filling up?--Yes; the First Commissioner has been so good as to let me have them this morning; I believe that the expense of the purification has been variously estimated at from about 30,000 l. up to 110,000 Z

117. I do not speak so much of the purification as the filling up of the bottom, so as to have a certain depth in every part of the Serpentine-I can give you some information upon that subject, but all these estimates will not be correct as to present circumstances, as it is quite possible, at the present moment, to get material very cheaply, or for nothing. There are three sources from which material can be obtained. There is a new railway about to be made, the Metropolitan Railway, an underground railway, and they have nowhere to place their material, and I should think that they would be very glad indeed to put it into the Serpentine for nothing, and perhaps pay something for leave to do so. The Middle Level Sewer is about to be made, and there is no place of deposit for the material which will come from it except at great distances; the contractors would be very willing, I have no doubt, to bring a large quantity of the material to the Serpentine. Then again, there is about to be a sewer made through the Park itself, and the material which comes from that sewer can be deposited in the Serpentine. Now these are circumstances which have never occurred before, and which are peculiar to the present moment, and in two or three years you will not be able to avail yourselves of them.

118. Sir Morton Peto.] I want to know what the estimate for filling up the Serpentine would be, irrespective of the question of purification?-It is not within my knowledge at this moment.

119. Chairman.] Will you be good enough to refer to the last paragraph of Mr. Page's report (the same being handed to the Witness):-This relates to another work; the formation of an island, and various other things; Mr. Page proposed to construct an island of the mud, so that it does not answer the question.

120. Sir Morton Peto.] You have rather anticipated a question I was about to ask you, as to the price at which material could be supplied at the present time for the filling up of the Serpentine. I wish to direct your attention to the Metropolitan Railway and the Middle Level Sewer; you appear to have viewed this matter with reference to them ?--Yes; having been concerned on the drainage question I am privy to the circumstances; then I have a general knowledge of the fact, that the Metropolitan Railway, after being long in a state of suspension, has now been actually commenced; I know also that there are difficulties as to a shoot for the excavated material.

121. Then, with regard to filling it up, to what extent would it be necessary to move the mud; would that depend upon the depth at which the water is required to be kept hereafter?-My own impression is, that no mud should be removed at all, excepting at the upper end, where, being exceedingly shallow, some mud must, of course, be removed to make it deep enough; where it is deep enough, I would not advise the mud to be touched; I think it would be a very injudicious thing to meddle with it.

122. To what extent, in your judgment, would it be necessary to remove the mud; what cubical contents?-I can state it hereafter.

123. Chairman.] I think you answered that question in your report, in the paragraph that I have marked (the report being handed to the Witness) ?—Yes. 124. Be good enough to read it?"The quantity of mud to be removed will

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5 March 1860,

T. Hawksley, Esq. be little short of 150,000 yards, and this one operation would cost at least 25,000, whilst the adjustment, and regulation, and levelling at the bottom, as proposed in some document forwarded to me, would cost probably 40,000 l. or 50,000 l. in addition." That is so. Those are the figures to be found in a document forwarded to me, with the exception of the first figure, namely, 150,000 yards, at 3 s. 4 d. per cubic yard.

125. Sir Joseph Paxton.] What depth do you think the Serpentine should generally be, supposing it to be partially filled up?-If the question is put with a view to the use of the bathers, who have been allowed for some years past to occupy the lake permissively, and not of right, I should have to consider the wants of the bathers in several aspects: first of all, there are the little boys, and then the men who cannot swim, and then the men who can swim, and they do not agree amongst themselves as to what they want, and next the place at which they would be allowed to bathe. My own notion is, that they should be allowed to bathe in the part above the bridge, and that part should be made fit and suitable for the purpose, and planted round. It is the most secluded part, and it should be properly formed into a basin, not destroying its ornamental character, and then the rest of the Serpentine might be left untouched; it would not be a very expensive operation, and to my mind it would effect the very object that is

necessary.

126. Nobody knows better than you that warm water is much lighter than cold water, and that water flows in proportion to its degrees of heat; that the circulation of hot water takes place by the hot water forcing its way, being a less dense body than the cold water at the bottom; at 10, or 12, or 14 feet deep, the water is much colder than at the surface, in very hot weather, and in water taken from the bottom of a lake at 14 feet below the surface, there would be a perceptible difference in the warmth; as that is the case, the mud underneath, of course, would be in the same dormant state, as the mud under the cold water would not be in action; you say that it is in the part where the water is very shallow; now, suppose you move the mud at the bottom of that part, and bring it to the surface, or anything like that, and expose it to the action of the atmosphere, would you not say that there would be in that a larger proportion of matter than on the outside, where the action of the heat would bring it to the surface?—If I understand the question, I should say, yes; but I am not quite sure that I very clearly understand it; because I do not know whether you allude to the kind of matter of which I have been speaking.

127. I mean the mud at the bottom of this lake, in the deep places; where the water is cold and dense, would not the mud brought to the surface by any process be different from the mud in the shallower parts?—Yes, certainly. There is no doubt that the mud cannot pass into a state of fermentation or putrefaction, unless assisted by heat.

128. With respect to the water passing down the Serpentine, you may remember the discussion which took place in the House of Commons last year; I understood that your plan then was to take the water out of some part of the Serpentine, and that you would put it in again?-Yes, I do remember the discussions; and I am not surprised at what you have said, for when I heard the discussion myself, I should have come to the same conclusion from the way in which it was stated; I should have thought that the water was simply to be churned backwards and forwards where the filter beds were, and not to be taken from one end and put into the other. I happened to be in the House at the time, and I know it was stated in a way that would have led me to the same conclusion.

129. With respect to the two millions of gallons per day, it will take the whole of the water out of the Serpentine in one month, as near as possible?—Yes.

130. Then is it your opinion that the water at the upper end, where the filter beds are, will all move down, and make the whole of the water precisely or something like the same sort of purity, or will it be 30 per cent. better at this end than at the other end?-It is difficult to state percentages, but I should say it would be 50 per cent. better at one end than at the other end.

131. I gather from your evidence, that if you had been called upon to give an opinion, you would have said that there was no necessity for putting any sort of filter bed. I think you stated to the Committee, that the water in the Serpentine is very nearly as good as the filtered water supplied to London? -No. The filtered

filtered water of the Serpentine is nearly as good as the filtered water supplied T. Hawksley, Esq. to London.

132. I perceive by the drawing, that you have jets at the other end of the Serpentine; and those jets are not at all connected with the filtering process. It is in fact a fountain process? It is a fountain process, and the way in which it is done is this. In consequence of the sewer overflows still existing, I have been under the necessity of making a channel under this central part (pointing to the drawing) in order, if there should be any overflow, to enable the sullage still to pass into the Serpentine, and the purified water will fall over from these large fountains into here (pointing to the drawing), and then, as a matter of course, it will reflow up that channel (pointing to the same). Then by means of another pump, I raise that purified water into a cistern, in the roof of this building (pointing to the same), and allow it to become distributed to all the fountains. There is one here (pointing to the same), another there, and two small ones there (pointing to the same).

133. What is the height of them:-About 12 feet.

134. Is there a pretty considerable quantity of water?-About 500 gallons a minute distributed to the fountains, and 1,400 gallons a minute to the filter beds.

135. Then one-fourth would be the fountain process?-Yes, that is to say, onefourth of the expense, so far as regards fuel; as regards the men's time and everything else, that would remain just the same.

136. At the time of year when there is no pumping going on, these fountains will be always still ?-Čertainly, but either of them can be detached from the other; you can raise the water from this fountain without using the filter beds, or use the filter beds without this fountain, or work the two together, that (pointing to the drawing) shows the tunnels.

137. These filter beds will be emptied once in three weeks, that is, they will be all emptied in that time, and every part be cleansed once in three weeks?Not usually; in the height of the summer it will be the case.

138. Would there be any stench from those beds in very hot weather?--No, as the water will be let off late at night; there are pipes communicating with these central tunnels from each filter bed, by which the water is let out overnight; then, in early morning the man will come and just perform this little operation, of scraping and taking the sand away, and washing it clean and bringing it back again.

139. Suppose that any difficulty with regard to smell should take place on account of the deposits, they could be readily cleaned every morning?--Yes.

140. Mr. Algernon Egerton.] I think you stated that there is no supply now from the Ranelagh Brook, except occasionally from an overflow of the sewer?Yes.

141. What fresh supply of water is there in the Serpentine. Are there any springs in it?—Yes, there are springs; and there is a considerable surface drainage from the Park, and there is also a supply, which has now become a very small one, from the Chelsea Water Company; they send some water into the Round Pond, and the overflow of that pond comes into the head of the Serpentine.

142. Have you estimated the amount of that supply-Yes; there is a return appended to my report.

143. Mr. Beach.] You consider that this plan would impart considerably more movement and agitation to the matter than at the present time?--Yes; the whole quantity of water would be changed every month.

144. That would have the effect, although not of entirely preventing the growth of vegetation, yet to render it more gradual and less prolific ?—Yes; very much to diminish its amount. If vegetation could be prevented it would be very injurious to the water itself, for the vegetation is the mode by which nature cleanses the water, and the means by which it removes organic impurities. 145. Lord John Manners.] I take it that you think the mud at the bottom is innocuous?—Yes.

146. Have you come to that conclusion from any experiments made by yourself, or by others?-Both from experiments made by myself and by Mr. Spencer; but there is a very good test that we can always obtain from observation: if the mud were in a putrescent state, and were fermenting, gases would be given out, which you would perceive in bubbles on the surface of the water, especially when

5 March 1860.